Cushioning mechanism for reciprocating beds.



` C. A. MGGAIN.- GUSHIONING MEGHANISM FOR REGIPROGATING BEDS.

APPLICATION FILED 18, 1909.

Patented. Dec. 28, 1909..

3 SHEETS-SHEET 1.

C. A. MGGAIN. GUSHIONING MEGHANISM FOR REGIPROGATING BEDS.

- APPLIATION FILED MARl 18, 1909. 944,492e

Patented Dec.28,1909.

3 SHEETS-SHEET 2.

ANDREW, s. mum

(LA. MGCAIN.

GUSHIONING MBGHANISM POR REGIPROGATING BEDS.

APPLICATION FILED MAR. 18, 1909.

Patented 1560.28, 1909.'

3 SHEETS-SHEET s;

@TLLSJ Y 2,11%,MJ4 TM Egal/@M07 CYRUS A. IVICCAIN,

OF OAK PARK, ILLINOIS, ASSIGNOR TO MIEI-ILE PRINTING PRESS & MANUFACTURING COMPANY, 0F CHICAGO, ILLINOIS, A CORPORATION 0F ILLINOIS.

CUSHIONING MECHANISM FOR RECIPROCATING BEDS.

Specification of Letters Patent.

Patented Dec. 28, 1909.

Application led March 18, 1909. Serial No. 484,100.

To all whom it may concern:

Be it known that I, CYRUs A. MCCAIN, a citizen of the United States, residing in Oak Park, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Cushioning Mechanism for Reciprocating Beds, of which the following is a specication.

This invention relates to the cushioning mechanism employed with reciprocating beds of printing presses, planing machines and the like, and is an improvement upon the construction shown in my U. S. Patent No. 7 88,931, of May 2nd, 1905. In the class of printing presses upon which these cushioning devices are customarily used, it is usual to have the air cylinders attached to each end of the frames or base, and also t0 apply air cushion rods to the bed, having heads or plungers mounted thereon, such heads or plungers being adapted to enter the air cylinders at the ends of the bed strokes and compress the air necessary to obviate the shock and strain comingron the mechanism as the bed is stopped and reversed. The difficulty heretofore met with in these cushioning devices has been to regulate the resistance automatically so'as to enable the presses to be operated at the varying speeds necessary for different work, so that too much resistance will not be present when slow speed is being used, and not enough resistance be present when the press is running at high speed.

In the present invention, I utilize as the means for governing the resistance, the speed at which the bed is reciprocated, so that when the bed is being used at high speed, the resistance will be increased, and when it is used at low speed, the resistance will be diminished. Thevnature of these devices by which I accomplish these results is fully disclosed in the accompanying description, and illustrated in the drawing forming a part thereof.

In the drawing, Figure 1 is a longitudinal section of a printing press embodying my invention and Fig. 2 is a plan view of the cushioning mechanism, the press bed being omitted. Fig. 3 is an enlarged section of the cushioning devices at one end of the press. Figs. 4 and 5 are sections on the lines 1- 4 and 5-5 respectively of Fig. 3. Fig. 6 is an end elevation of one of the auxiliary cylinders. Fig. 7 is a section on the line 7 7 of Fig. 6 and Fig. 8 is a transverse vertical section of the press.

In the drawing, 10 represents the reciprocating bed of the press, and 11 the impression cylinder. The bed travels upon runways 12, and its reversing movements are cushioned by air cylinders 13, 14, 15 and 16, two at each end of the press. There are air cushion rods for each pair of these cylinders, those indicated at 17 being employed with the cylinders having auxiliary cylinders attached, and those marked 18. being used with cylinders having no auxiliary cylinders. The pairs of cylinders at each end of the press are connected by pipes 19, so that the same air pressure will be present in both of each pair. The heads of the air cushion rods are lndicated at 20 and are uniform in their construction. The rods are supported from the reciprocating type bed by brackets 21, and are rigidly held in such brackets so that the heads 20 are forced into the air cushion cylinders at each end of the bed stroke, imprisoning in so doing, the air in the cylinders and compressing the same.

The cylinders 13 and 14 are each accompanied by an auxiliary cylinder, that with cylinder 13 being shown at 22, and that accompanying cylinder 14 being shown 'at 23. These cylinders are exactly alike in construction, and I have illustrated one of them fully at Fig. 3. The cylinders 13 and 14: communicate with their respective auxiliary cylinders through pipes 24, the entrance to the auxiliary chamber being controlled by spring pressed valves 25 and 26. Upon the first of these, the burden of resisting the entrance of the air from the main to the auxiliary cylinder rests, and the other is adapted to yield to the pressure existing in the auxiliary cylinder wherein that pressure becomes greater than the pressure in the main cylinder, so that the air can then flow back into the latter from the auxiliary cylinder. The valve 25 is in ring form, supported by a spider or tripod 27, the arms of which converge and are united to a sleeve 28 sliding in the central opening of a stationary cap 29 attached to the end of the cylinder. The sleeve 28 is fitted upon the end of a longitudinally movable rod 30 extending through the farther end of the cylinder where it is surrounded by a stuffing box 31. This rod carries a collar 32 between which and the sleeve 28 is a spring 33, the

gradually,

tension of which is exerted upon the sleeve and :acts to :keep the valve :25 pressed -iipen its sea-t. ,A second collar 3l upon the rod limits the movements of the rod 30 in one direction. The valve 26 is more ullly described later on.

lilith the rod '30, I employ devices whereby it may be shifted longitudinally .to .increase the tension on the spring 33 when the speed of the press is augmented so as to require increased resistance from the cushioning devices. The construction which l have adopted for this purpose is that shown, and 'is as follows: Upon the air cushion rod 17 'I place a sliding device which l call the knocker, and which preferably consists of two weights l35 one lat each side of the bracket 2l by which the rod is attached to the bed, the weights vbeing joined rigidly together by a metal strap '36. The weights are loosely litted to .the .rod so they slide freely thereon, and at the outer ,side fot each weight I place light springs '37, which are confined on `the 'rods by collars 38.. This knocker quickly acquires the momentum of the bed, and y'by reason thereof will continue to Vmove under the power .thereof at the high speed of the bed after .the latter has been slowed down, so that it is peculiarly yadapted to perform the timct'ion of governing the air cushions las Vhereinafter stated. ils the speed of the press becomes rapid, the depending leg or 'striker 39 attached to the strap 36 midway between .the ends or momentum movement of .the knocker, strikes the end of a wedge 450, which is a horizontally movable plate sliding in a runway il attached to .the top of one end of the cylinder 22. By this action of the striker, the wedge is caused to move against the top 42a of 42 pivoted at 43 and .arranged at right angles to the wedge and having an inclined edge 421 insertedbetween the end of .the rod 30 and the stationary bracket 44E attached to the outside of cylinder '22. The wedge when thus actuated by the striker, turns the cam on its pivot so that its inclined .edge forces -therod 30 back toward the valve 25. kThe tension of the spring -3-3 is thus increased, so that .the valve 2.5 opens less `freely, and the resistance to the entrance of air from the main cylinder is augmented. The extent to which the resistance may be thus increased, is dependent as will be understood upon the speed of .the press, :the higher the speed the greater the movements imparted to the knocker, the wedge and the cam, ,and the greater is the resistance caused by the air cushioning devices, the resist-ance being thus proportionate to the speed at all times. The knocker imparts repeated impulses to the wedge as the speed of the press increases, and consequently :the action of the cam increases the tension on spring i3,3

but it is adapted to yhold the'tension indefinitely and until released as hereinafter stated. e

The auxiliary cylinder is relieved of its air whenever the pressurein the ina-in .cyl-

inder becomes less than that in the/former,-

th-e valve 26 then opening automatically and allowing :the escape of the air into the mainv son with valve 25, so as -to open the vpassage Y between the cylinders.

'When the press is lslowed down or stopped the attendant releases the tension automatically put upon the spring `33 by the devices described, so that the wedge cam and rod 30 can all return to normal positions by the foot lever :50 .of the brake kof the press. Vhen tliis lever is depressed it carries down a companion lever :5l and a rod attached to the latter. The rod 52 is Yattached at its upper end 'to an arm 53 onshaft i511, and shaft "5ft carries another arm 55 which ac-tjs on the v.cam V4t2 when' the .lever 50 is actuated, and forcestfhe .camback to normal position, and in this movement V`the point 42a of the cam act-s against the lincline of plate 40 .and retracts the same. i

'The air lconnections between the two main cylinders `at one end of the press are very plainly shown at Fig. 8 and Ia'lso sometimes apply a pressure indicator to these .connections ladapted -to enable theoperator to watch the variations in :the air pressure.

I claim zi 'The Combination with .the valves for relieving the pressure of the air cushioning Cylinders of a printing press, of govern-mg mechanism regulating the resistance of said valves, and a device iter .controlling said mechanism such device 'being freely attached to the bed and permitted to move 'independently lby momentum at the ends of the bed strokes.V

v2. The combination with the valves forV relieving the pressure of the air cushioning cylinders .of a printing press, of governing mechanism regulating the resistance ,of said valves, and a device forl controlling said mechanism, such device being attached to the bed and free to move independently :by momentum at the ends of the strokes.

3. The combination with the valves for relieving the pressure of the air cushioning cylinder of a printing press, oi a governing mechanism regulating the resistance of sai valves said governing 4mechanism acting V1n accor ance with the speed of the 'press and embracing a device carlried bythe bedand lll) adapted to slide independently of the bed by momentum received from the bed.

4. The combination With the air cushion cylinders and plungers of a printing press, auxiliary cylinders communicating with the air cushion cylinders, valves controlling such communication, means for increasing the resistance to opening of such valves and governing mechanism determining the action of said means in accordance with the speed of the press, said governing mechanism embracing a device moving with the bed and also having freedom to continue its motion in obedience to momentum independently of the bed.

5. The combination with the air cushion cylinders and plungers of a printing press, of auxiliary cylinders communicating With the air cushion cylinders, valves controlling such communication, means for increasing the resistance to opening of such valves and governing mechanism determining the action of said means in accordance with the speed of the press, said governing mechanism embracing a device moving With the bed and having freedom to move also by momentum.

6. The combination With the air cushion cylinders and plungers of a printing press, of auxiliary cylinders communicating with the air cushion cylinders, valves controlling 30 such communication, means for increasing the resistance to opening of such valves, a governing device moving with the bed of the press and also having freedom to move by momentum, and devices whereby the momentum of the governing device actuates the means for increasing the resistance of said valves.

CYRUS A. MCCAIN. Witnesses:

ROY D. LAMB, PERCY G. SHAW. 

